1. Field of the Invention
The present invention relates to a semiconductor device and more particularly to an integrated circuit having a zinc sulfide electroluminescent layer grown directly on a silicon based control circuit.
2. Description of the Prior Art
The use of electroluminescent (EL) display elements with thin film transistor control circuitry is known technology. For example, U.S. Pat. No. 4,042,854, issued to Luo, et al. on Aug. 16, 1977, discloses a thin film transistor array and an electroluminescent phosphor layer disposed between a pair of elongated electrodes for exciting the phosphor layer. Similarly, U.S. Pat. No. 4,110,664, issued to Asars, et al. on Aug. 29, 1978, discloses an electroluminescent bar graph display module comprised of a multistage thin film transistor and plurality of electroluminescent display elements.
U.S. Pat. No. 4,523,189, issued to Takahara, et al. on June 11, 1985, discloses a thin film EL device comprising a zinc sulfide/manganese phosphor layer sandwiched between electrode layers and positioned on top of a plurality of N-channel MOS transistors.
It is also known technology to utilize a liquid crystal display (LCD) with a thin film semiconductor device. For example, U.S. Pat. No. 4,486,748, issued to Nanomura, et al. on Dec. 4, 1984, discloses an LCD layer driven by a thin film transistor array and an electrode. U.S. Pat. Nos. 4,644,338 and 4,740,782, issued to Aoki, et al. on Feb. 17, 1987 and Apr. 26, 1988, respectively, disclose a dot matrix LCD driven by a plurality of thin film transistors and requiring a reduced number of terminals for external connection.
The construction of semiconductor devices having other types of light sources is also known technology. U.S. Pat. No. 4,608,696, issued to Law, et al. on Aug. 26, 1986, discloses semiconductor laser and a metal-insulator-semiconductor field effect transistor (MISFET) built as a monolithic device using planar fabrication techniques. U.S. Pat. No. 4,719,498, issued to Wada, et al. on Jan. 12, 1988, discloses an optoelectric integrated circuit in which the optical element, e.g., a laser diode, and the electronic semiconductor elements are formed nearly flatly on a single substrate.
All of the semiconductor devices disclosed in this list of prior art require a plurality of electrodes and nonactive conductive parts or layers within the semiconductor device in order to activate the electroluminescent element.
H. S. Reehal and C. B. Thomas, in a paper published in Solid-State Electronics (GB), Vol. 29, No. 4, pp. 429-36 (April 1986), disclose the use of a zinc sulfide electroluminescent layer positioned directly on a silicon substrate without the use of intervening conductive parts. However, the silicon substrate does not include control circuit elements for driving the electroluminescent layer.